pizzas = ['huotui', 'liulian', 'boluo', 'kaochi', 'datui']
subpizzas1 = pizzas[:3]
print(subpizzas1)
subpizzas2 = pizzas[1:4]
print(subpizzas2)
subpizzas3 = pizzas[-3:]
print(subpizzas3)

friend_pizzas = pizzas[:]
pizzas.append("xiangjiao")
friend_pizzas.append("caimei")
print(friend_pizzas)
print(pizzas)

for pizza in friend_pizzas:
    print(pizza)